key_value1.c

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/*!
   \file lib/gis/key_value1.c

   \brief Subroutines for Key/Value management.

   (C) 2001-2008, 2012 by the GRASS Development Team

   This program is free software under the GNU General Public License
   (>=v2).  Read the file COPYING that comes with GRASS for details.

   \author CERL
 */

#include <string.h>
#include <stdlib.h>
#include <grass/gis.h>

/*!
   \brief Allocate and initialize Key_Value structure

   \return pointer to allocated Key_Value structure
 */
struct Key_Value *G_create_key_value(void)
{
    struct Key_Value *kv = G_malloc(sizeof(struct Key_Value));
    G_zero(kv, sizeof(struct Key_Value));
    
    return kv;
}

/*!
   \brief Set value for given key

   \param key key to be set up
   \param value value for given key
   \param[in,out] kv Key_value structure to be modified
 */
void G_set_key_value(const char *key, const char *value, struct Key_Value *kv)
{
    int n;

    if (!key)
        return;

    for (n = 0; n < kv->nitems; n++)
        if (strcmp(key, kv->key[n]) == 0)
            break;

    if (n == kv->nitems) {
        if (n >= kv->nalloc) {
            size_t size;

            if (kv->nalloc <= 0)
                kv->nalloc = 8;
            else
                kv->nalloc *= 2;

            size = kv->nalloc * sizeof(char *);
            kv->key = G_realloc(kv->key, size);
            kv->value = G_realloc(kv->value, size);
        }

        kv->key[n] = G_store(key);
        kv->value[n] = G_store(value);
        kv->nitems++;
        return;
    }

    if (kv->value[n])
        G_free(kv->value[n]);

    kv->value[n] = value ? G_store(value) : NULL;
}

/*!
   \brief Find given key (case sensitive)

   \param key key to be found
   \param kv pointer to Key_value structure

   \return pointer to value of key
   \return NULL if no key found
 */
const char *G_find_key_value(const char *key, const struct Key_Value *kv)
{
    int n;

    if (!kv)
        return NULL;
    
    for (n = 0; n < kv->nitems; n++)
        if (strcmp(key, kv->key[n]) == 0)
            return kv->value[n][0] ? kv->value[n] : NULL;
    
    return NULL;
}

/*!
   \brief Free allocated Key_Value structure

   \param[in] kv Key_Value structure to be freed
 */
void G_free_key_value(struct Key_Value *kv)
{
    int n;

    if (!kv)
        return;

    for (n = 0; n < kv->nitems; n++) {
        G_free(kv->key[n]);
        G_free(kv->value[n]);
    }
    G_free(kv->key);
    G_free(kv->value);
    kv->nitems = 0;             /* just for safe measure */
    kv->nalloc = 0;
    G_free(kv);
}